Ehrlichial invasin for immunization, diagnosis, and cell delivery

Abstract

Disclosed are vaccines containing one or more immunogenic polypeptides derived from an EtpE protein from an Ehrlichia sp. or nucleic acid encoding these polypeptides. Also disclosed is a method for vaccinating a subject against Ehrlichia sp. that involves administering to the subject a composition comprising any of the disclosed vaccines. Also disclosed is a method for diagnosing and/or monitoring the treatment of Ehrlichiosis in a subject that comprising assaying a biological sample (e.g., blood, serum, or plasma sample) from the subject for the presence of an antibody that specifically binds an EtpE polypeptide. Also disclosed are methods for delivering a therapeutic or diagnostic agent to a cell in a subject that involves conjugating the agent, or a delivery vehicle comprising the agent, to polypeptide containing the C-terminal domain of an EtpE protein.

What is claimed is: 
     
       1. A vaccine, comprising
 one or more polypeptides comprising an amino acid sequence having at least 70% identity to an amino acid sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:3, SEQ ID NO:5, or an immunogenic fragment thereof capable of eliciting an immune response against an  Ehrlichia  sp.; and 
 a pharmaceutically acceptable adjuvant. 
 
     
     
       2. The vaccine of  claim 1 , wherein the one or more polypeptides comprise an amino acid sequence having at least 70% identity to SEQ ID NO:2 (residues 1656-1963 of SEQ ID NO:1), SEQ ID NO:4 (residues 1408-1510 of SEQ ID NO:3), SEQ ID NO:6 (residues 1410-1710 of SEQ ID NO:5), or a an immunogenic fragment thereof capable of eliciting an immune response against an  Ehrlichia  sp. 
     
     
       3. The vaccine of  claim 1 , comprising at least two polypeptides collectively capable of eliciting an immune response against at least two  Ehrlichia  sp. 
     
     
       4. The vaccine of  claim 3 , comprising at least three polypeptides collectively capable of eliciting an immune response against at least three  Ehrlichia  sp. 
     
     
       5. The vaccine of  claim 1 , wherein the vaccine is capable of eliciting an immune response against  Ehrlichia chaffeensis.    
     
     
       6. The vaccine of  claim 5 , wherein at least one of the one or more polypeptides comprise SEQ ID NO:1, SEQ ID NO:2, or an immunogenic fragment thereof capable of eliciting an immune response against  Ehrlichia chaffeensis.    
     
     
       7. The vaccine of  claim 1 , wherein the vaccine is capable of eliciting an immune response against  Ehrlichia canis.    
     
     
       8. The vaccine of  claim 7 , wherein at least one of the one or more polypeptides comprise SEQ ID NO:3, or an immunogenic fragment thereof capable of eliciting an immune response against  Ehrlichia canis.    
     
     
       9. The vaccine of  claim 1 , wherein the vaccine is capable of eliciting an immune response against  Ehrlichia ruminantium.    
     
     
       10. The vaccine of  claim 9 , wherein at least one of the one or more polypeptides comprise SEQ ID NO:5, or an immunogenic fragment thereof capable of eliciting an immune response against  Ehrlichia ruminantium.    
     
     
       11. The vaccine of  claim 1 , wherein the vaccine is capable of eliciting an immune response against  Ehrlichia muris, Ehrlichia ewingii , or a combination thereof. 
     
     
       12. The vaccine of  claim 1 , wherein the adjuvant is selected from the group consisting of Quil A, aluminum salts, squalene, virosomes, and combinations thereof. 
     
     
       13. The vaccine of  claim 1 , wherein the immune stimulant comprises cytokines, growth factors, chemokines.